Separation of phenolic compounds from roselle (Hibiscus sabdariffa) calyces with aqueous two-phase extraction based on sodium citrate and polyethylene glycol or acetone

Phenolic compounds (PC) attract great interest due to their nutraceutical properties. In order to evaluate the potential of aqueous two-phase extraction (ATPE) to separate PC from extracts of roselle (Hibiscus sabdariffa) calyces, attending reduction of sugars, systems based on sodium citrate/polyethylene glycol 2000 (Peg2000) and sodium citrate/acetone, were compared. Binodal diagrams were developed to evaluate separations at 25°C. The system based on Peg2000 was the best option. With 15.83% of polymer and 25.16% of sodium citrate, the recovering of 94.73% of PC was achieved in the polymeric phase, eliminating 92.89% of sugars in the saline one.